codman

Superhorizon perturbations: A possible explanation of the Hubble–Lemaître Tension and the Large Scale Anisotropy of the Universe

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Current cosmological observations point to a serious discrepancy between the observed Hubble parameter obtained using direct and cosmic microwave background radiation (CMBR) measurements. Besides this, the so called Hubble–Lemaître tension, we also find considerable evidence in diverse cosmological observables that indicate violation of the cosmological principle. In this paper, we suggest that both these discrepancies …

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Real-time detection of anomalies in large-scale transient surveys

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New time-domain surveys, such as the Rubin Observatory Legacy Survey of Space and Time (LSST), will observe millions of transient alerts each night, making standard approaches of visually identifying new and interesting transients infeasible. We present two novel methods of automatically detecting anomalous transient light curves in real-time. Both methods are based on the simple …

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COSMOS2020: A panchromatic view of the Universe to z∼10 from two complementary catalogs

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The Cosmic Evolution Survey (COSMOS) has become a cornerstone of extragalactic astronomy. Since the last public catalog in 2015, a wealth of new imaging and spectroscopic data has been collected in the COSMOS field. This paper describes the collection, processing, and analysis of this new imaging data to produce a new reference photometric redshift catalog. …

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KiDS-1000 Cosmology: machine learning -accelerated constraints on Interacting Dark Energy with CosmoPower

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We derive constraints on a coupled quintessence model with pure momentum exchange from the public ∼1000 deg2 cosmic shear measurements from the Kilo-Degree Survey and the Planck 2018 Cosmic Microwave Background data. We compare this model with ΛCDM and find similar χ2 and log-evidence values. We accelerate parameter estimation by sourcing cosmological power spectra from the neural network emulator CosmoPower. We highlight the …

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Writing Scientific Papers in Astronomy

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A paper has been written, about writing papers in Astronomy! It may sound ironic, but there is a lot of specialised skills going into writing in an academic style optimised to transmit scientific savoir-faire, methods, algorithms, assumptions, context of research and more. Writing papers is often one of those skills that is acquired by exposure, …

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Exploring and interrogating astrophysical data in virtual reality

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Scientists across all disciplines increasingly rely on machine learning algorithms to analyse and sort datasets of ever increasing volume and complexity. Although trends and outliers are easily extracted, careful and close inspection will still be necessary to explore and disentangle detailed behaviour, as well as identify systematics and false positives. We must therefore incorporate new …

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Rapidly quenched galaxies in the Simba cosmological simulation and observations

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A wide range of mechanisms have been put forward to explain the quenching of star formation in galaxies with cosmic time, however, the true balance of responsible mechanisms remains unknown. The identification and study of galaxies that have shut down their star formation on different timescales might elucidate which mechanisms dominate at different epochs and …

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